I just installed Active SMART - I see all kinds of statistics - but no temperature? I have a WD 80 Gb.
Some hard drives do not support temperature monitoring through the S.M.A.R.T. For such drives Active SMART shows "N/A" instead of temperature and all the temperature options are disabled. Per our records temperature monitoring do not support some models of Western Digital and Maxtor hard drives.

Unfortunately, I cannot see SMART attributes for any of my SCSI drives.

SCSI drives do not report information about S.M.A.R.T. attributes, they use another method of reporting S.M.A.R.T. status. Please read Active SMART and SCSI drives article about this.

Please advise if Active SMART can handle RAID arrays and in particular RAID 0+1.

Active SMART supports SCSI RAID arrays and does not support IDE (ATA) RAID arrays. The special version of Active SMART with SCSI and IDE RAID support will be available soon.

Does Active SMART supports Promise Ultra 100 controller (or controllers on HighPoint chipsets)?
Current version does not support drives on external IDE controllers, that uses HighPoint or Promise chipsets, but we work on this and support for HighPoint and possible Promise IDE RAID cards will be added to our software.

What is the difference between the Active SMART software and the S.M.A.R.T. in my BIOS?
The S.M.A.R.T. in your BIOS only checks the status of the drive at boot time, Active SMART gives you real-time protection while you work with very flexible notification abilities, logging abilities and many other unique features.